Wave guide with crystal diode socket having captive clamping means



y 3 1958 c. P. DOME'NICHINI ETAL 2,834,884

WAVE GUIDE WITH CRYSTAL mom: SOCKET HAVING CAPTIVE CLAMPING MEANS FiledApril 8. 1954 /NVENTO/25 CARLO R DOMEN/CH/N/ JOSEPH BA/(U o lvsv UnitedStates Patent WAVE GUIDE WITH CRYSTAL DIODE SOCKET HAVING CAPTIVECLAMPING MEANS Carlo P. Domenichini, Lexington, and Joseph Bakura,

Watertown, Mass., assignors to Raytheon Manufacturing Company, Waltham,Mass, a corporation of Delaware Application April 8, 1954, Serial No.421,721

1 Claim. (Cl. 250-31) This invention relates to microwave radiation, andparticularly to the construction of those components which perform themodulating or mixing function in a high frequency wave guide assembly.For such purpose, it is customary to employ a crystal composed of amaterial which lends itself to the accomplishment of the heterodyningfunction entering into the process of extracting a lower frequency bandof signal energy from a carrier wave of much higher frequency.

The invention is characterized by the provision of quickly attachableand readily removable means for firmly holding such a crystallineelement in good electrical contact with the terminal ,of a conductorleading from the wave guide to an I. F. amplifier or other point ofutilization of the heterodyned output. A feature of the construction isthe use of parts which do not require threading or screwing operationsfor insertion or removal, and which are self-captivating withoutreliance upon chains or similar appendages awkward to manipulate.

These and other characteristics of the invention will be betterunderstood upon reference to the following description of the embodimentof, the invention illustrated in the accompanying drawings wherein:

Fig. 1 is an elevation view of a radiant energy transmitting wave guidestructure of a type to which the invention is applicable; 7

Fig. 2 is a longitudinal sectional view of one end of the wave guidestructure of Fig. 1 showing an embodiment of the invention; and

Fig. 3 is a top plan view of the assembly of Fig. 2.

In these drawings, reference character 11 designates a microwave guidingconduit having at its outer end a coupling flange 12 for engagement withan antenna feed conduit (not shown) adapted to cooperate with aconventional reflector element (also not shown) for the radiation ofhigh frequency radiant energy. Intermediate the ends of the wave guide11 there is disposed a transmitting oscillator assembly including aklystron 13, a surrounding heat controlling oven 14, and a coaxialtransducer 15 connecting the klystron generating cavity with thelongitudinal wave guide 11. Also intermediate the ends of the wave guide11 there is disposed a second resonant cavity structure 17 constitutinga second frequency control cooperating with the principal wave guidesection 11 and cooperating with the crystal mixer or modulation assemblylocated near the inner end of the wave guide 11 and constituting thesubject matter of the present invention.

As shown best in Figs. 2 and'3, the mixer assembly includes a crystalelement 21 of cylindrical contour and terminating in a smallercylindrical portion 22 adapted to enter within and to be frictionallyand resiliently grasped by a plurality of resilient metallic fingers 23extending upwardly from a metallic conducting element 24 having at itslower end a terminal formation 25 adapted to receive the end of acurrent-conducting wire or cable by which signal-carrying energy issupplied from the crystal 2,834,884 Patented May 13, 1958 ice 21 and thewave guide 11. This conductor 24 is in alignment with the longitudinalaxis of the crystal 21 and is retained in such alignment by thesurrounding assembly including an inner guide bushing 27 fitting withinan orifice formed in the cylindrical wall of the wave guide 11 inalignment with a second orifice adapted to receive the crystal 21. Thebushing 27 is retained in its orifice by interengagement with a shoulderformed internally of the outer cylindrical casing 29, which casing isthermally united to the wall of the wave guide 11 along the outercircular shoulder 31. The casing 29 has a transversely extendingpartition 33 spaced from bushing 27 by an insulating element 30, thepart 33 serving as an abutment for flange 34 on conductor 24. Adielectric spacer 36 is retained in position by a circular retainingspring 37 fitting within a circular groove 38 formed on the innercylindrical surface of the casing 29. Other insulation 38a surroundsflange 34.

The means for retaining the crystal 21 in operative engagement with thefingers 23 of the conducting element 24 includes a bifurcated metalliccap having its longitudinally extending portions 41 and 42 in registrywith diametrically opposite portions of a circular groove 43 extendingabout the periphery of a metallic bushing 44 whose central bore receivesthe crystal 21 and whose inner reduced end 45 fits within and isthermally united to the upper orifice previously referred to. The caphas an additional portion of circular contour uniting the previouslydescribed portion with a crystal engaging upper portion resting on theend surface of the crystal and, by reason of the resiliency of themetal, causing a retaining pressure to be exerted along the axis of thecrystal, thus insuring its continuing conductive relationship with thefingers 23. The outer ends of the fingers 41 and 42 have inwardlyturning portions 47 and 48 of suflicient extent to serve as limitingelements when the cap is withdrawn laterally of the bushing 44 asufiicient distance to free the upper end of the cap from engagementwith the upper end of the crystal. When this has been done, the crystal21 is free to be withdrawn from the assembly for inspection orreplacement by a counterpart. During such an operation, the cap, whileWithdrawn, cannot actually escape from the assembly in view of theretaining action of the toe elements 47 and 48. Thus, the assembly ismaintained intact during a crystal withdrawing and replacing operationand without the necessity of resorting to retention chains or othercumbersome and obstiucting devices.

The wave guide assembly of Fig. 1 may be supported upon a panel orbracket (not shown) by inserting the cylinder 29 into an opening in suchpanel or bracket, and clamping the cylinder thereto by means of clampingnuts 51 and 52. These nuts may then be secured by tightening lockwashers 53 and 54. All these parts are threaded upon the threadedexterior of cylinder 29.

This invention may be applied to either a transmitting or receiving waveguide, or to any equivalent structure to which energy pickup by crystalmeans is desirable. The invention, in any of its applications, is notlimited to the particular details of construction, materials andprocesses described, as many equivalents will suggest themselves tothose skilled in the art. It is, accordingly, desired that the appendedclaims be given a broad interpretation commensurate with the scope ofthe invention within the art.

What is claimed is:

In an electromagnetic wave energy guiding structure, the improvementcomprising first and second spaced bushings secured to said wave guidingstructure, said bushings having aligned central apertures thereincommunicating with the interior of said wave guiding structure, a con-3; q ounted. i h nh eamr u e f. id s nd bu ing, said conductorterminating in resilient gripping elements, a crystal element positionedin the aperture of said first .bushing and projecting within said waveguiding structure, said crystal elementhaving a portion thereofengagedby-said gripping element's establishing an electrical juncture,said firstbushing having a peripheral groove therein, a slidable memberhaving a pair of spaced parallel fingers carrying a resilient element,said fingers cooperating with saidperipheral groove whereby saidresilient element may be slidably positioned over the aperture in saidfirst bushing to bear upon the exposed end of said crystal element, saidparallel fingers being of suflicient length to permit said resilientelement to be displaced entirely clear of said aperture, and means 4ecur o. firifiasem. t l ads. hereqi. o. pr v t separation of saidslidable mernber from said first bushing.

References Cited in the file of this patent UNITED STATES, PATENTS483,221 um et al. Sept. 27, 1 92 1,334,212 Becker et a1. Mar. 16, 19202,291,674 Alden Aug. 4, 1942 2,469,222 Atwood etal. May 3, 19492,544,842 Lawson Mar. 13, 1951 2,636,120 Brod et al; Apr. 21, 19532,642,494 Zaslavsky et a1. June 16, 1953 FOREIGN PATENTS 979,826 FranceDec. 13, 1950

